ssl/ssl_sess.c

   1 /* ssl/ssl_sess.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <stdio.h>
  60 #include "lhash.h"
  61 #include "rand.h"
  62 #include "ssl_locl.h"
  63
  64 #ifndef NOPROTO
  65 static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *s);
  66 static void SSL_SESSION_list_add(SSL_CTX *ctx,SSL_SESSION *s);
  67 #else
  68 static void SSL_SESSION_list_remove();
  69 static void SSL_SESSION_list_add();
  70 #endif
  71
  72 static int ssl_session_num=0;
  73 static STACK *ssl_session_meth=NULL;
  74
  75 SSL_SESSION *SSL_get_session(ssl)
  76 SSL *ssl;
  77         {
  78         return(ssl->session);
  79         }
  80
  81 int SSL_SESSION_get_ex_new_index(argl,argp,new_func,dup_func,free_func)
  82 long argl;
  83 char *argp;
  84 int (*new_func)();
  85 int (*dup_func)();
  86 void (*free_func)();
  87         {
  88         ssl_session_num++;
  89         return(CRYPTO_get_ex_new_index(ssl_session_num-1,
  90                 &ssl_session_meth,
  91                 argl,argp,new_func,dup_func,free_func));
  92         }
  93
  94 int SSL_SESSION_set_ex_data(s,idx,arg)
  95 SSL_SESSION *s;
  96 int idx;
  97 char *arg;
  98         {
  99         return(CRYPTO_set_ex_data(&s->ex_data,idx,arg));
 100         }
 101
 102 char *SSL_SESSION_get_ex_data(s,idx)
 103 SSL_SESSION *s;
 104 int idx;
 105         {
 106         return(CRYPTO_get_ex_data(&s->ex_data,idx));
 107         }
 108
 109 SSL_SESSION *SSL_SESSION_new()
 110         {
 111         SSL_SESSION *ss;
 112
 113         ss=(SSL_SESSION *)Malloc(sizeof(SSL_SESSION));
 114         if (ss == NULL)
 115                 {
 116                 SSLerr(SSL_F_SSL_SESSION_NEW,ERR_R_MALLOC_FAILURE);
 117                 return(0);
 118                 }
 119         memset(ss,0,sizeof(SSL_SESSION));
 120
 121         ss->references=1;
 122         ss->timeout=60*5+4; /* 5 minute timeout by default */
 123         ss->time=time(NULL);
 124         ss->prev=NULL;
 125         ss->next=NULL;
 126         CRYPTO_new_ex_data(ssl_session_meth,(char *)ss,&ss->ex_data);
 127         return(ss);
 128         }
 129
 130 int ssl_get_new_session(s, session)
 131 SSL *s;
 132 int session;
 133         {
 134         SSL_SESSION *ss=NULL;
 135
 136         if ((ss=SSL_SESSION_new()) == NULL) return(0);
 137
 138         /* If the context has a default timeout, use it */
 139         if (s->ctx->session_timeout != 0)
 140                 ss->timeout=SSL_get_default_timeout(s);
 141
 142         if (s->session != NULL)
 143                 {
 144                 SSL_SESSION_free(s->session);
 145                 s->session=NULL;
 146                 }
 147
 148         if (session)
 149                 {
 150                 if (s->version == SSL2_CLIENT_VERSION)
 151                         {
 152                         ss->ssl_version=SSL2_VERSION;
 153                         ss->session_id_length=SSL2_SSL_SESSION_ID_LENGTH;
 154                         }
 155                 else if (s->version == SSL3_VERSION)
 156                         {
 157                         ss->ssl_version=SSL3_VERSION;
 158                         ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
 159                         }
 160                 else if (s->version == TLS1_VERSION)
 161                         {
 162                         ss->ssl_version=TLS1_VERSION;
 163                         ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
 164                         }
 165                 else
 166                         {
 167                         SSLerr(SSL_F_SSL_GET_NEW_SESSION,SSL_R_UNSUPPORTED_SSL_VERSION);
 168                         SSL_SESSION_free(ss);
 169                         return(0);
 170                         }
 171
 172                 for (;;)
 173                         {
 174                         SSL_SESSION *r;
 175
 176                         RAND_bytes(ss->session_id,ss->session_id_length);
 177                         CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
 178                         r=(SSL_SESSION *)lh_retrieve(s->ctx->sessions,
 179                                 (char *)ss);
 180                         CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
 181                         if (r == NULL) break;
 182                         /* else - woops a session_id match */
 183                         }
 184                 }
 185         else
 186                 {
 187                 ss->session_id_length=0;
 188                 }
 189
 190         s->session=ss;
 191         ss->ssl_version=s->version;
 192
 193         return(1);
 194         }
 195
 196 int ssl_get_prev_session(s,session_id,len)
 197 SSL *s;
 198 unsigned char *session_id;
 199 int len;
 200         {
 201         SSL_SESSION *ret=NULL,data;
 202
 203         /* conn_init();*/
 204         data.ssl_version=s->version;
 205         data.session_id_length=len;
 206         if (len > SSL_MAX_SSL_SESSION_ID_LENGTH)
 207                 return(0);
 208         memcpy(data.session_id,session_id,len);;
 209
 210         if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_LOOKUP))
 211                 {
 212                 CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
 213                 ret=(SSL_SESSION *)lh_retrieve(s->ctx->sessions,(char *)&data);
 214                 CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
 215                 }
 216
 217         if (ret == NULL)
 218                 {
 219                 int copy=1;
 220
 221                 s->ctx->sess_miss++;
 222                 ret=NULL;
 223                 if ((s->ctx->get_session_cb != NULL) &&
 224                         ((ret=s->ctx->get_session_cb(s,session_id,len,&copy))
 225                                 != NULL))
 226                         {
 227                         s->ctx->sess_cb_hit++;
 228
 229                         /* The following should not return 1, otherwise,
 230                          * things are very strange */
 231                         SSL_CTX_add_session(s->ctx,ret);
 232                         /* auto free it */
 233                         if (!copy)
 234                                 SSL_SESSION_free(ret);
 235                         }
 236                 if (ret == NULL) return(0);
 237                 }
 238
 239         if (ret->cipher == NULL)
 240                 {
 241                 char buf[5],*p;
 242                 unsigned long l;
 243
 244                 p=buf;
 245                 l=ret->cipher_id;
 246                 l2n(l,p);
 247                 if ((ret->ssl_version>>8) == SSL3_VERSION_MAJOR)
 248                         ret->cipher=ssl_get_cipher_by_char(s,&(buf[2]));
 249                 else
 250                         ret->cipher=ssl_get_cipher_by_char(s,&(buf[1]));
 251                 if (ret->cipher == NULL)
 252                         return(0);
 253                 }
 254
 255         /* If a thread got the session, then 'swaped', and another got
 256          * it and then due to a time-out decided to 'Free' it we could
 257          * be in trouble.  So I'll increment it now, then double decrement
 258          * later - am I speaking rubbish?. */
 259         CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
 260
 261         if ((long)(ret->time+ret->timeout) < (long)time(NULL)) /* timeout */
 262                 {
 263                 s->ctx->sess_timeout++;
 264                 /* remove it from the cache */
 265                 SSL_CTX_remove_session(s->ctx,ret);
 266                 SSL_SESSION_free(ret);          /* again to actually Free it */
 267                 return(0);
 268                 }
 269
 270         s->ctx->sess_hit++;
 271
 272         /* ret->time=time(NULL); */ /* rezero timeout? */
 273         /* again, just leave the session
 274          * if it is the same session, we have just incremented and
 275          * then decremented the reference count :-) */
 276         if (s->session != NULL)
 277                 SSL_SESSION_free(s->session);
 278         s->session=ret;
 279         return(1);
 280         }
 281
 282 int SSL_CTX_add_session(ctx,c)
 283 SSL_CTX *ctx;
 284 SSL_SESSION *c;
 285         {
 286         int ret=0;
 287         SSL_SESSION *s;
 288
 289         /* conn_init(); */
 290         CRYPTO_add(&c->references,1,CRYPTO_LOCK_SSL_SESSION);
 291
 292         CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
 293         s=(SSL_SESSION *)lh_insert(ctx->sessions,(char *)c);
 294
 295         /* Put on the end of the queue unless it is already in the cache */
 296         if (s == NULL)
 297                 SSL_SESSION_list_add(ctx,c);
 298
 299         /* If the same session if is being 're-added', Free the old
 300          * one when the last person stops using it.
 301          * This will also work if it is alread in the cache.
 302          * The references will go up and then down :-) */
 303         if (s != NULL)
 304                 {
 305                 SSL_SESSION_free(s);
 306                 ret=0;
 307                 }
 308         else
 309                 {
 310                 ret=1;
 311
 312                 if (SSL_CTX_sess_get_cache_size(ctx) > 0)
 313                         {
 314                         while (SSL_CTX_sess_number(ctx) >
 315                                 SSL_CTX_sess_get_cache_size(ctx))
 316                                 {
 317                                 if (!SSL_CTX_remove_session(ctx,
 318                                         ctx->session_cache_tail))
 319                                         break;
 320                                 else
 321                                         ctx->sess_cache_full++;
 322                                 }
 323                         }
 324                 }
 325         CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
 326         return(ret);
 327         }
 328
 329 int SSL_CTX_remove_session(ctx,c)
 330 SSL_CTX *ctx;
 331 SSL_SESSION *c;
 332         {
 333         SSL_SESSION *r;
 334         int ret=0;
 335
 336         if ((c != NULL) && (c->session_id_length != 0))
 337                 {
 338                 CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
 339                 r=(SSL_SESSION *)lh_delete(ctx->sessions,(char *)c);
 340                 if (r != NULL)
 341                         {
 342                         ret=1;
 343                         SSL_SESSION_list_remove(ctx,c);
 344                         }
 345
 346                 CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
 347
 348                 if (ret)
 349                         {
 350                         r->not_resumable=1;
 351                         if (ctx->remove_session_cb != NULL)
 352                                 ctx->remove_session_cb(ctx,r);
 353                         SSL_SESSION_free(r);
 354                         }
 355                 }
 356         else
 357                 ret=0;
 358         return(ret);
 359         }
 360
 361 void SSL_SESSION_free(ss)
 362 SSL_SESSION *ss;
 363         {
 364         int i;
 365
 366         if(ss == NULL)
 367             return;
 368
 369         i=CRYPTO_add(&ss->references,-1,CRYPTO_LOCK_SSL_SESSION);
 370 #ifdef REF_PRINT
 371         REF_PRINT("SSL_SESSION",ss);
 372 #endif
 373         if (i > 0) return;
 374 #ifdef REF_CHECK
 375         if (i < 0)
 376                 {
 377                 fprintf(stderr,"SSL_SESSION_free, bad reference count\n");
 378                 abort(); /* ok */
 379                 }
 380 #endif
 381
 382         CRYPTO_free_ex_data(ssl_session_meth,(char *)ss,&ss->ex_data);
 383
 384         memset(ss->key_arg,0,SSL_MAX_KEY_ARG_LENGTH);
 385         memset(ss->master_key,0,SSL_MAX_MASTER_KEY_LENGTH);
 386         memset(ss->session_id,0,SSL_MAX_SSL_SESSION_ID_LENGTH);
 387         if (ss->cert != NULL) ssl_cert_free(ss->cert);
 388         if (ss->peer != NULL) X509_free(ss->peer);
 389         if (ss->ciphers != NULL) sk_free(ss->ciphers);
 390         memset(ss,0,sizeof(*ss));
 391         Free(ss);
 392         }
 393
 394 int SSL_set_session(s, session)
 395 SSL *s;
 396 SSL_SESSION *session;
 397         {
 398         int ret=0;
 399         SSL_METHOD *meth;
 400
 401         if (session != NULL)
 402                 {
 403                 meth=s->ctx->method->get_ssl_method(session->ssl_version);
 404                 if (meth == NULL)
 405                         meth=s->method->get_ssl_method(session->ssl_version);
 406                 if (meth == NULL)
 407                         {
 408                         SSLerr(SSL_F_SSL_SET_SESSION,SSL_R_UNABLE_TO_FIND_SSL_METHOD);
 409                         return(0);
 410                         }
 411
 412                 if (meth != s->method)
 413                         {
 414                         if (!SSL_set_ssl_method(s,meth))
 415                                 return(0);
 416                         session->timeout=SSL_get_default_timeout(s);
 417                         }
 418
 419                 /* CRYPTO_w_lock(CRYPTO_LOCK_SSL);*/
 420                 CRYPTO_add(&session->references,1,CRYPTO_LOCK_SSL_SESSION);
 421                 if (s->session != NULL)
 422                         SSL_SESSION_free(s->session);
 423                 s->session=session;
 424                 /* CRYPTO_w_unlock(CRYPTO_LOCK_SSL);*/
 425                 ret=1;
 426                 }
 427         else
 428                 {
 429                 if (s->session != NULL)
 430                         {
 431                         SSL_SESSION_free(s->session);
 432                         s->session=NULL;
 433                         }
 434                 }
 435         return(ret);
 436         }
 437
 438 long SSL_SESSION_set_timeout(s,t)
 439 SSL_SESSION *s;
 440 long t;
 441         {
 442         if (s == NULL) return(0);
 443         s->timeout=t;
 444         return(1);
 445         }
 446
 447 long SSL_SESSION_get_timeout(s)
 448 SSL_SESSION *s;
 449         {
 450         if (s == NULL) return(0);
 451         return(s->timeout);
 452         }
 453
 454 long SSL_SESSION_get_time(s)
 455 SSL_SESSION *s;
 456         {
 457         if (s == NULL) return(0);
 458         return(s->time);
 459         }
 460
 461 long SSL_SESSION_set_time(s,t)
 462 SSL_SESSION *s;
 463 long t;
 464         {
 465         if (s == NULL) return(0);
 466         s->time=t;
 467         return(t);
 468         }
 469
 470 typedef struct timeout_param_st
 471         {
 472         SSL_CTX *ctx;
 473         long time;
 474         LHASH *cache;
 475         } TIMEOUT_PARAM;
 476
 477 static void timeout(s,p)
 478 SSL_SESSION *s;
 479 TIMEOUT_PARAM *p;
 480         {
 481         if ((p->time == 0) || (p->time > (s->time+s->timeout))) /* timeout */
 482                 {
 483                 /* The reason we don't call SSL_CTX_remove_session() is to
 484                  * save on locking overhead */
 485                 lh_delete(p->cache,(char *)s);
 486                 SSL_SESSION_list_remove(p->ctx,s);
 487                 s->not_resumable=1;
 488                 if (p->ctx->remove_session_cb != NULL)
 489                         p->ctx->remove_session_cb(p->ctx,s);
 490                 SSL_SESSION_free(s);
 491                 }
 492         }
 493
 494 void SSL_CTX_flush_sessions(s,t)
 495 SSL_CTX *s;
 496 long t;
 497         {
 498         unsigned long i;
 499         TIMEOUT_PARAM tp;
 500
 501         tp.ctx=s;
 502         tp.cache=SSL_CTX_sessions(s);
 503         if (tp.cache == NULL) return;
 504         tp.time=t;
 505         CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
 506         i=tp.cache->down_load;
 507         tp.cache->down_load=0;
 508         lh_doall_arg(tp.cache,(void (*)())timeout,(char *)&tp);
 509         tp.cache->down_load=i;
 510         CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
 511         }
 512
 513 int ssl_clear_bad_session(s)
 514 SSL *s;
 515         {
 516         if (    (s->session != NULL) &&
 517                 !(s->shutdown & SSL_SENT_SHUTDOWN) &&
 518                 !(SSL_in_init(s) || SSL_in_before(s)))
 519                 {
 520                 SSL_CTX_remove_session(s->ctx,s->session);
 521                 return(1);
 522                 }
 523         else
 524                 return(0);
 525         }
 526
 527 /* locked by SSL_CTX in the calling function */
 528 static void SSL_SESSION_list_remove(ctx,s)
 529 SSL_CTX *ctx;
 530 SSL_SESSION *s;
 531         {
 532         if ((s->next == NULL) || (s->prev == NULL)) return;
 533
 534         if (s->next == (SSL_SESSION *)&(ctx->session_cache_tail))
 535                 { /* last element in list */
 536                 if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
 537                         { /* only one element in list */
 538                         ctx->session_cache_head=NULL;
 539                         ctx->session_cache_tail=NULL;
 540                         }
 541                 else
 542                         {
 543                         ctx->session_cache_tail=s->prev;
 544                         s->prev->next=(SSL_SESSION *)&(ctx->session_cache_tail);
 545                         }
 546                 }
 547         else
 548                 {
 549                 if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
 550                         { /* first element in list */
 551                         ctx->session_cache_head=s->next;
 552                         s->next->prev=(SSL_SESSION *)&(ctx->session_cache_head);
 553                         }
 554                 else
 555                         { /* middle of list */
 556                         s->next->prev=s->prev;
 557                         s->prev->next=s->next;
 558                         }
 559                 }
 560         s->prev=s->next=NULL;
 561         }
 562
 563 static void SSL_SESSION_list_add(ctx,s)
 564 SSL_CTX *ctx;
 565 SSL_SESSION *s;
 566         {
 567         if ((s->next != NULL) && (s->prev != NULL))
 568                 SSL_SESSION_list_remove(ctx,s);
 569
 570         if (ctx->session_cache_head == NULL)
 571                 {
 572                 ctx->session_cache_head=s;
 573                 ctx->session_cache_tail=s;
 574                 s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
 575                 s->next=(SSL_SESSION *)&(ctx->session_cache_tail);
 576                 }
 577         else
 578                 {
 579                 s->next=ctx->session_cache_head;
 580                 s->next->prev=s;
 581                 s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
 582                 ctx->session_cache_head=s;
 583                 }
 584         }
 585